TechniqueDecision principleInvestingDecision-making
State, for each holding, what would have to happen for the thesis to be right
Scott Miller · Greenhaven Road Capital's Q2 2026 letter, on changing how the portfolio is built · 2026
The idea
Greenhaven Road's mid-2026 letter is written in a weak year, and its most useful feature is structural. For each large holding the manager says where his view departs from sell-side consensus, names the evidence he relies on, statutory insurance filings and court records rather than company presentations, and closes by stating what would have to happen for the thesis to be right, so a reader can check it against later events. The portfolio changes are specific too: lower concentration, more near-term catalysts, taking profits when prices run ahead of events. A thesis that names its own test is a different kind of document from one that names only its hopes.
Write the thesis with its test attached: the variant view, the evidence, and the event that would confirm or refute it.
When it works
Writing a stock pitch, reviewing a portfolio, and any investment committee that wants to know what would change your mind.
When it may fail
The letter's rights do not allow an excerpt here, so read the original for the wording. Naming a test is easy; honouring it when the test fails is the hard part the letter is about.
How to use it
Add a final section to every pitch headed what would prove me wrong, with dates. Then review it on those dates. The one-page write-up guide leaves room for it.
Where it came from
Letter Greenhaven Road Capital's Q2 2026 letter, on changing how the portfolio is built · Scott Miller
What the source says. Miller frames each large holding by where his view departs from consensus and the evidence he relies on, sets out specific portfolio changes, and ends by stating for each holding what would have to happen for the thesis to be right.
Connected ideas
Puts it to work
A good decision and a good outcome are separate thingsJudge a decision by what was knowable when it was made, and keep the outcome in a separate column.
Says something similar
A bad year separated into its causes: which mistakes were mine and which were the marketSeparate a bad year into your errors and the market's mood, name the errors specifically, and say whether the method changes.
Concepts
Put it to work on L3VLUP
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